The couple, who wish to remain anonymous, found $10 million worth of gold coins that date back to the Gold Rush. The couple found the coins concealed in rusty old cans half buried in the ground while walking their dog in their yard. In the can was 1,400 $20 gold pieces, 50 $10 gold pieces and four $5 gold pieces. The coins have a face value of around $28,000, but are expected to go for much more at auction, reports The Chicago Tribune.

“The first thing the family did after finding all the cans was rebury them in a cooler under their woodpile,” David McCarthy, a numismatist from the firm that inspected the coins, told the San Francisco Chronicle. “They were terrified and had to think about what to do.”

The couple plans to sell most of the gold coins and keep some for themselves. Several of the coins will go on display at the American Numismatic Association show in Atlanta that takes place later this month. The couple said that the money from the gold coins will help them keep their house and that some of the money will go to charity, The Tribune notes.